org.tribuo

Class CategoricalInfo

java.lang.Object

org.tribuo.SkeletalVariableInfo

org.tribuo.CategoricalInfo

All Implemented Interfaces:

Serializable, Cloneable, VariableInfo

Direct Known Subclasses:

CategoricalIDInfo

public class CategoricalInfo
extends SkeletalVariableInfo

Stores information about Categorical features.

Contains a mapping from values to observed counts for that value, has an initial optimisation for the binary case to reduce memory consumption.

Can be transformed into a RealInfo if there are too many unique observed values.

Does not contain an id number, but can be transformed into CategoricalIDInfo which does contain an id number.

Note that the synchronization in this class only protects instantiation where CDF and values are recomputed. Care should be taken if data is read while observe(double) is called.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected double[]	cdf The CDF to sample from.
protected long	observedCount The count of the observed value if it's only seen a single one.
protected double	observedValue The observed value if it's only seen a single one.
static int	THRESHOLD The default threshold for converting a categorical info into a RealInfo.
protected long	totalObservations The total number of observations (including zeros).
protected Map<Double,com.oracle.labs.mlrg.olcut.util.MutableLong>	valueCounts The occurrence counts of each value.
protected double[]	values The values array.

Fields inherited from class org.tribuo.SkeletalVariableInfo

count, name

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	CategoricalInfo(CategoricalInfo info) Constructs a deep copy of the supplied categorical info.
protected	CategoricalInfo(CategoricalInfo info, String newName) Constructs a deep copy of the supplied categorical info, with the new feature name.
	CategoricalInfo(String name) Constructs a new empty categorical info for the supplied feature name.

Method Summary

Modifier and Type	Method and Description
CategoricalInfo	copy() Returns a copy of this variable info.
double	frequencyBasedSample(Random rng, long totalObservations) Samples a value from this feature according to the frequency of observation.
double	frequencyBasedSample(SplittableRandom rng, long totalObservations) Samples a value from this feature according to the frequency of observation.
RealInfo	generateRealInfo() Generates a RealInfo using the currently observed counts to calculate the min, max, mean and variance.
long	getObservationCount(double value) Gets the number of times a specific value was observed, and zero if this value is unknown.
int	getUniqueObservations() Gets the number of unique values this CategoricalInfo has observed.
CategoricalIDInfo	makeIDInfo(int id) Generates a VariableIDInfo subclass which represents the same feature.
protected void	observe(double value) Records the value.
CategoricalInfo	rename(String newName) Rename generates a fresh VariableInfo with the new name.
String	toString()
double	uniformSample(SplittableRandom rng) Sample a value uniformly from the range of this variable.

Methods inherited from class org.tribuo.SkeletalVariableInfo

equals, getCount, getName, hashCode

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

THRESHOLD

public static final int THRESHOLD

The default threshold for converting a categorical info into a RealInfo.

See Also:

Constant Field Values

valueCounts

protected Map<Double,com.oracle.labs.mlrg.olcut.util.MutableLong> valueCounts

The occurrence counts of each value.

observedValue

protected double observedValue

The observed value if it's only seen a single one.

observedCount

protected long observedCount

The count of the observed value if it's only seen a single one.

values

protected transient double[] values

The values array.

totalObservations

protected transient long totalObservations

The total number of observations (including zeros).

cdf

protected transient double[] cdf

The CDF to sample from.

Constructor Detail

CategoricalInfo

public CategoricalInfo(String name)

Constructs a new empty categorical info for the supplied feature name.

Parameters:

name - The feature name.

CategoricalInfo

protected CategoricalInfo(CategoricalInfo info)

Constructs a deep copy of the supplied categorical info.

Parameters:

info - The info to copy.

CategoricalInfo

protected CategoricalInfo(CategoricalInfo info,
                          String newName)

Constructs a deep copy of the supplied categorical info, with the new feature name.

Parameters:

info - The info to copy.

newName - The new feature name.

Method Detail

observe

protected void observe(double value)

Description copied from class: SkeletalVariableInfo

Records the value.

Overrides:

observe in class SkeletalVariableInfo

Parameters:

value - The observed value.

getObservationCount

public long getObservationCount(double value)

Gets the number of times a specific value was observed, and zero if this value is unknown.

Parameters:

value - The value to check.

Returns:

The count of times this value was observed, zero otherwise.

getUniqueObservations

public int getUniqueObservations()

Gets the number of unique values this CategoricalInfo has observed.

Returns:

An int representing the number of unique values.

generateRealInfo

public RealInfo generateRealInfo()

Generates a RealInfo using the currently observed counts to calculate the min, max, mean and variance.

Returns:

A RealInfo representing the data in this CategoricalInfo.

copy

public CategoricalInfo copy()

Description copied from interface: VariableInfo

Returns a copy of this variable info.

Returns:

A copy.

makeIDInfo

public CategoricalIDInfo makeIDInfo(int id)

Description copied from interface: VariableInfo

Generates a VariableIDInfo subclass which represents the same feature.

Parameters:

id - The id number.

Returns:

A VariableInfo with the same information, plus the id.

rename

public CategoricalInfo rename(String newName)

Description copied from interface: VariableInfo

Rename generates a fresh VariableInfo with the new name. The name forms part of the hashcode so it's immutable in the object.

Parameters:

newName - The new name.

Returns:

A VariableInfo subclass with the new name.

uniformSample

public double uniformSample(SplittableRandom rng)

Description copied from interface: VariableInfo

Sample a value uniformly from the range of this variable.

Parameters:

rng - The rng to use.

Returns:

A sample from this variable.

frequencyBasedSample

public double frequencyBasedSample(SplittableRandom rng,
                                   long totalObservations)

Samples a value from this feature according to the frequency of observation.

Parameters:

rng - The RNG to use.

totalObservations - The observations including the implicit zeros.

Returns:

The sampled value.

frequencyBasedSample

public double frequencyBasedSample(Random rng,
                                   long totalObservations)

Samples a value from this feature according to the frequency of observation.

Parameters:

rng - The RNG to use.

totalObservations - The observations including the implicit zeros.

Returns:

The sampled value.

toString

public String toString()

Overrides:

toString in class SkeletalVariableInfo